enetc: Remove Tx checksumming offload code

Tx checksumming has been defeatured and completely removed
from the h/w reference manual. Made a little cleanup for the
TSE case as this is complementary code.
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Link: https://lore.kernel.org/r/20201103140213.3294-1-claudiu.manoil@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/enetc/enetc.c

@@ -47,40 +47,6 @@ netdev_tx_t enetc_xmit(struct sk_buff *skb, struct net_device *ndev)
 	return NETDEV_TX_OK;
 }
 
-static bool enetc_tx_csum(struct sk_buff *skb, union enetc_tx_bd *txbd)
-{
-	int l3_start, l3_hsize;
-	u16 l3_flags, l4_flags;
-
-	if (skb->ip_summed != CHECKSUM_PARTIAL)
-		return false;
-
-	switch (skb->csum_offset) {
-	case offsetof(struct tcphdr, check):
-		l4_flags = ENETC_TXBD_L4_TCP;
-		break;
-	case offsetof(struct udphdr, check):
-		l4_flags = ENETC_TXBD_L4_UDP;
-		break;
-	default:
-		skb_checksum_help(skb);
-		return false;
-	}
-
-	l3_start = skb_network_offset(skb);
-	l3_hsize = skb_network_header_len(skb);
-
-	l3_flags = 0;
-	if (skb->protocol == htons(ETH_P_IPV6))
-		l3_flags = ENETC_TXBD_L3_IPV6;
-
-	/* write BD fields */
-	txbd->l3_csoff = enetc_txbd_l3_csoff(l3_start, l3_hsize, l3_flags);
-	txbd->l4_csoff = l4_flags;
-
-	return true;
-}
-
 static void enetc_unmap_tx_buff(struct enetc_bdr *tx_ring,
 				struct enetc_tx_swbd *tx_swbd)
 {
@@ -146,22 +112,16 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb,
 	if (do_vlan || do_tstamp)
 		flags |= ENETC_TXBD_FLAGS_EX;
 
-	if (enetc_tx_csum(skb, &temp_bd))
-		flags |= ENETC_TXBD_FLAGS_CSUM | ENETC_TXBD_FLAGS_L4CS;
-	else if (tx_ring->tsd_enable)
+	if (tx_ring->tsd_enable)
 		flags |= ENETC_TXBD_FLAGS_TSE | ENETC_TXBD_FLAGS_TXSTART;
 
 	/* first BD needs frm_len and offload flags set */
 	temp_bd.frm_len = cpu_to_le16(skb->len);
 	temp_bd.flags = flags;
 
-	if (flags & ENETC_TXBD_FLAGS_TSE) {
-		u32 temp;
-
-		temp = (skb->skb_mstamp_ns >> 5 & ENETC_TXBD_TXSTART_MASK)
-			| (flags << ENETC_TXBD_FLAGS_OFFSET);
-		temp_bd.txstart = cpu_to_le32(temp);
-	}
+	if (flags & ENETC_TXBD_FLAGS_TSE)
+		temp_bd.txstart = enetc_txbd_set_tx_start(skb->skb_mstamp_ns,
+							  flags);
 
 	if (flags & ENETC_TXBD_FLAGS_EX) {
 		u8 e_flags = 0;
@@ -1897,8 +1857,7 @@ static void enetc_kfree_si(struct enetc_si *si)
 static void enetc_detect_errata(struct enetc_si *si)
 {
 	if (si->pdev->revision == ENETC_REV1)
-		si->errata = ENETC_ERR_TXCSUM | ENETC_ERR_VLAN_ISOL |
-			     ENETC_ERR_UCMCSWP;
+		si->errata = ENETC_ERR_VLAN_ISOL | ENETC_ERR_UCMCSWP;
 }
 
 int enetc_pci_probe(struct pci_dev *pdev, const char *name, int sizeof_priv)

drivers/net/ethernet/freescale/enetc/enetc.h

@@ -147,9 +147,8 @@ struct enetc_msg_swbd {
 
 #define ENETC_REV1	0x1
 enum enetc_errata {
-	ENETC_ERR_TXCSUM	= BIT(0),
-	ENETC_ERR_VLAN_ISOL	= BIT(1),
-	ENETC_ERR_UCMCSWP	= BIT(2),
+	ENETC_ERR_VLAN_ISOL	= BIT(0),
+	ENETC_ERR_UCMCSWP	= BIT(1),
 };
 
 #define ENETC_SI_F_QBV BIT(0)

drivers/net/ethernet/freescale/enetc/enetc_hw.h

@@ -374,8 +374,7 @@ union enetc_tx_bd {
 		__le16 frm_len;
 		union {
 			struct {
-				__le16 l3_csoff;
-				u8 l4_csoff;
+				u8 reserved[3];
 				u8 flags;
 			}; /* default layout */
 			__le32 txstart;
@@ -398,41 +397,37 @@ union enetc_tx_bd {
 	} wb; /* writeback descriptor */
 };
 
-#define ENETC_TXBD_FLAGS_L4CS	BIT(0)
-#define ENETC_TXBD_FLAGS_TSE	BIT(1)
-#define ENETC_TXBD_FLAGS_W	BIT(2)
-#define ENETC_TXBD_FLAGS_CSUM	BIT(3)
-#define ENETC_TXBD_FLAGS_TXSTART BIT(4)
-#define ENETC_TXBD_FLAGS_EX	BIT(6)
-#define ENETC_TXBD_FLAGS_F	BIT(7)
+enum enetc_txbd_flags {
+	ENETC_TXBD_FLAGS_RES0 = BIT(0), /* reserved */
+	ENETC_TXBD_FLAGS_TSE = BIT(1),
+	ENETC_TXBD_FLAGS_W = BIT(2),
+	ENETC_TXBD_FLAGS_RES3 = BIT(3), /* reserved */
+	ENETC_TXBD_FLAGS_TXSTART = BIT(4),
+	ENETC_TXBD_FLAGS_EX = BIT(6),
+	ENETC_TXBD_FLAGS_F = BIT(7)
+};
 #define ENETC_TXBD_TXSTART_MASK GENMASK(24, 0)
 #define ENETC_TXBD_FLAGS_OFFSET 24
+
+static inline __le32 enetc_txbd_set_tx_start(u64 tx_start, u8 flags)
+{
+	u32 temp;
+
+	temp = (tx_start >> 5 & ENETC_TXBD_TXSTART_MASK) |
+	       (flags << ENETC_TXBD_FLAGS_OFFSET);
+
+	return cpu_to_le32(temp);
+}
+
 static inline void enetc_clear_tx_bd(union enetc_tx_bd *txbd)
 {
 	memset(txbd, 0, sizeof(*txbd));
 }
 
-/* L3 csum flags */
-#define ENETC_TXBD_L3_IPCS	BIT(7)
-#define ENETC_TXBD_L3_IPV6	BIT(15)
-
-#define ENETC_TXBD_L3_START_MASK	GENMASK(6, 0)
-#define ENETC_TXBD_L3_SET_HSIZE(val)	((((val) >> 2) & 0x7f) << 8)
-
 /* Extension flags */
 #define ENETC_TXBD_E_FLAGS_VLAN_INS	BIT(0)
 #define ENETC_TXBD_E_FLAGS_TWO_STEP_PTP	BIT(2)
 
-static inline __le16 enetc_txbd_l3_csoff(int start, int hdr_sz, u16 l3_flags)
-{
-	return cpu_to_le16(l3_flags | ENETC_TXBD_L3_SET_HSIZE(hdr_sz) |
-			   (start & ENETC_TXBD_L3_START_MASK));
-}
-
-/* L4 csum flags */
-#define ENETC_TXBD_L4_UDP	BIT(5)
-#define ENETC_TXBD_L4_TCP	BIT(6)
-
 union enetc_rx_bd {
 	struct {
 		__le64 addr;

drivers/net/ethernet/freescale/enetc/enetc_pf.c

@@ -714,22 +714,16 @@ static void enetc_pf_netdev_setup(struct enetc_si *si, struct net_device *ndev,
 	ndev->watchdog_timeo = 5 * HZ;
 	ndev->max_mtu = ENETC_MAX_MTU;
 
-	ndev->hw_features = NETIF_F_SG | NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
+	ndev->hw_features = NETIF_F_SG | NETIF_F_RXCSUM |
 			    NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX |
 			    NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_LOOPBACK;
-	ndev->features = NETIF_F_HIGHDMA | NETIF_F_SG |
-			 NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
+	ndev->features = NETIF_F_HIGHDMA | NETIF_F_SG | NETIF_F_RXCSUM |
 			 NETIF_F_HW_VLAN_CTAG_TX |
 			 NETIF_F_HW_VLAN_CTAG_RX;
 
 	if (si->num_rss)
 		ndev->hw_features |= NETIF_F_RXHASH;
 
-	if (si->errata & ENETC_ERR_TXCSUM) {
-		ndev->hw_features &= ~NETIF_F_HW_CSUM;
-		ndev->features &= ~NETIF_F_HW_CSUM;
-	}
-
 	ndev->priv_flags |= IFF_UNICAST_FLT;
 
 	if (si->hw_features & ENETC_SI_F_QBV)

drivers/net/ethernet/freescale/enetc/enetc_vf.c

@@ -120,22 +120,16 @@ static void enetc_vf_netdev_setup(struct enetc_si *si, struct net_device *ndev,
 	ndev->watchdog_timeo = 5 * HZ;
 	ndev->max_mtu = ENETC_MAX_MTU;
 
-	ndev->hw_features = NETIF_F_SG | NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
+	ndev->hw_features = NETIF_F_SG | NETIF_F_RXCSUM |
 			    NETIF_F_HW_VLAN_CTAG_TX |
 			    NETIF_F_HW_VLAN_CTAG_RX;
-	ndev->features = NETIF_F_HIGHDMA | NETIF_F_SG |
-			 NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
+	ndev->features = NETIF_F_HIGHDMA | NETIF_F_SG | NETIF_F_RXCSUM |
 			 NETIF_F_HW_VLAN_CTAG_TX |
 			 NETIF_F_HW_VLAN_CTAG_RX;
 
 	if (si->num_rss)
 		ndev->hw_features |= NETIF_F_RXHASH;
 
-	if (si->errata & ENETC_ERR_TXCSUM) {
-		ndev->hw_features &= ~NETIF_F_HW_CSUM;
-		ndev->features &= ~NETIF_F_HW_CSUM;
-	}
-
 	/* pick up primary MAC address from SI */
 	enetc_get_primary_mac_addr(&si->hw, ndev->dev_addr);
 }